Broaching machine



7 Sheets-Sheet l M. FOX

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Patented Nov. 11, 1952 BROACHING MACHINE Myer Fox, Hudson, Mass., assignor to The Lapointe Machine Tool Company, Hudson, Mass., a corporation of Maine Application February 17, 1950, Serial No. 144,644

7 Claims.

This invention relates to a hydraulic broaching machine in which relative movement between a broach and a piece of work will produce a roughing cut in one range of operation and a nishing cut in an adjacent but diierent range of operation. The machine is more commonly used in surface Ibroaching operations.

In the preferred form, both ranges may also be combined to give a single full-stroke range of substantially double length. Provision is also made for effecting successive broaching operations in the roughing range onlyy successive breaching operations in the nishing range only, or immediately successive roughing and finishing operations, all at the desire and discretion of the operator.

I also provide means by which each control circuit remains operative for its full intended period of operation and regardless of the intervening release of the manual control switch.

My invention further relates to varrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims. y

Fig. 1 is a diagrammatic View illustrating the operation of my improved breaching machine;

Figs. 2 to 7 are views similar to Fig. 1 but showing the positions of the control devices under different conditions of operation and at successive points;

Fig. 8 is a diagrammatic plan View, taken in part along the line 8-8 in Fig. 1;

Fig. 9 is a side elevation of a normally open control switch in the return circuit; and

Fig. 10 is a similar view of a normally closed control switch in the cut circuit.

Referring to Fig. 1, I have indicated a breach holder ||l adapted to be reciprocated lby a piston in a hydraulic cylinder l2. The upper end of the cylinder 2 is connected by a pipe |4 to one side of a reversing valve V and the lower end of the cylinder I2 is similarly connected by a pipe i6 to the opposite side of the valve V.

The valve V may be of any usual or commercial construction and is arranged to be shifted to the left in Fig. 1 by a solenoid 20 and to be shifted to the right by a solenoid 2 I. The valve V has a supply pipe 22 and a discharge pipe 23 and will return to mid or neutral position when both solenoid circuits are open.

When the movable member or piston of the valve V is shifted to the left as shown in Fig. 1, the supply pipe 22 is connected to the pipe |4 and the pipe I6 is connected to the discharge 2 pipe 23. If the valve piston is shifted to the right, the connections are reversed as shown in Fig. 3.

The direction of travel of the broach holder I0 is thus determined by the setting of the valve V, which in turn is controlled by the selective activation of the solenoids 20 and 2|.

One line wire L is connected direct to the solenoids 20 and 2| as shown in Fig. 1, and a second line wire L is connected to the solenoids 20 and 2| through wires 30 and 3| and through a series of selective switches interposed in said wires.

Switches S3, Si and S5 are interposed in series in the wire 30, and switches Sl and S8 are interposed in a .by-pass connection 32 around the switches S3 and S1. Switches S4, S9, S|| and S6 are interposed in series in the line wire 3|, and switches S2, SIG and SI2 are interposed in a by-pass connection 33 around the switches S4, S9 and SI The switches SI, S2, S3 and S4 are separately operated automatically by dogs DI, D2, D3 and D4, each adjustable lengthwise of the breach holder I. The switches SI to S4 and the dogs DI to D4 are arranged out of vertical alignment, as indicated in Fig. 8, so that the dog DI controls the switch Sl only, and that each of the other dogs similarly controls its own switch.

The switches S5 and S6 are normally open and are selectively closed manually to start the cut and return strokes respectively.

The switches S1, S8, S9 and Sl are simultaneously shifted, so that the switches S'l and S9 are closed and the switches S8 and S||l are open in one position, and so that all of these switches are reversed in a second position. These switches may be operated manually by means of a knob 35.

The switches S|| and SI2 are operated simultaneously and manually by a knob 36, one of these switches being closed when the other is opened.

The switches S2 and S4 may be of the construction shown in Fig. 9, where the cross bar 40 is operated through a bell crank 4| from a tumbler 42, which is shifted anti-clockwise .by a descending dog, as D2. The switch is returned to the normal and open position of Fig. 9 by the ydog D2, as the dog moves upward on its return stroke.

When the tumbler 42 is moved anti-clockwise, the pin 44 strikes one edge of the free arm of the bell crank 4| and pulls the cross bar 40 down to close the circuit between the switch terminals. When the tumbler 42 is returned to the position shown in Fig. 9, the pin 45 strikes the free arm of the bell crank 4| on its opposite edge and lifts the cross bar 40 away from the terminals, thus breaking the circuit through the switch.

The switches SI and S3 are of an alternative construction as shown in Fig. 10, in which the cross bar 50 is normally raised to engage the switch terminals when the tumbler 5I is in the normal position shown in Fig. 10. The cross bar 50 is lowered to break the circuit through the switch when the tumbler 5| is shifted anti-clockwise.

When the broach holder I is in fully raised or starting position, all of the switch tumblers are in the positions shown in Figs. 9 and 10 and at the top in Figs. 1 and 6. The positions of the tumblers and cross bars of the different switches at different points in the further operation of the machine are as indicated in the small figures above the diagrams in Figs. 2 to 5 and 1.

The switch S5 is the starting or cut switch, which is normally held open by a spring 60 and which may be manually closed by depressing a knob 6|. When the knob BI is depressed, the cross bar G2 of the switch S5 closes the switch circuit between the associated switch terminals in the wire 30 and also projects a steel plunger 63 into a solenoid coil CI which is connected by wires 64 and 65 to the wire 3G at opposite sides of a resistance R. If the switches S3 and S1 in the wire 3U are closed or if the switches SI and S8 in the wire 32 are closed, the closing of the switch S5 completes a circuit between the line wires L and L and through the solenoid 20. In either case, the closing of the circuit also closes the circuit through the wire E4, solenoid coil CI and wire 65, which energizes the solenoid coil CI, which coil thereafter holds the switch S5 closed, even after manual pressure on the knob 6| has ceased. The resistance R insures that enough current ows through coil CI to hold the switch S5 closed.

The completion of the described circuit causes the valve V to shift to the left, so that the hydraulic connections are as indicated in Fig. l. The circuit remains closed until either the switch SI or the switch S3 is opened by a dog on the broach holder I.

The switch S5 is the return switch, normally held open by a spring 1 acting against a knob 1I. A cross bar 12 engages terminals in the wire 3| when depressed, and the cross bar supports a plunger 13 which is simultaneously projected into a solenoid coil C2. The coil C2 is connected by wires 14 and 15 to the wire 3| at each side of a resistance R2.

The normally open switches S5 and SB are momentarily closed manually at the beginning of the cut and return strokes respectively.

The switches S1 and S8 are alternately disposed, and the selective manual closing of these switches determines the portion of the travel of the piston II in which the broaches are operative. If the switch S1 is closed, the broaches are reciprocated in the roughing range of broach travel, and if the switch S8 is closed, the broaches are reciprocated in the finish range or may be on full-stroke, as will be explained.

As the broach travels along its roughing stroke, the switch S4 in the wire 3| will be closed by the dog D4, and the switch S3 will be thereafter opened by the dog D3 (Fig. 2) as the roughing stroke is completed.

A return stroke can then be started by manually depressing the knob 1| to close the switch S6 (Fig. 3), and the switch S6 will be held closed by the holding coil C2 until the switch S4 is opened by a dog D4.

Switches S9 and SIG close their respective circuits alternately, and are operated manually and simultaneously with the switches S1 and S8 to determine whether the machine shall operate in the rough or nish range. The switches SII and SI2 are operated manually to close their respective circuits alternately. When the switch SI2 is closed, the machine operates with a short stroke, either rough or nish, and when the switch SII is closed, the machine operates with a full stroke.

The relative positions of the various switches at different points in the operation of the machine and under different operating conditions are clearly shown in the diagrammatic views of Figs. 1 to 7 n Fig. 1 the parts are shown in the position at the start of a cutting stroke over a short rough range. The switch I2 is closed to eect short travel, the switches 1 and 9 are closed to locate the stroke in the rough range, and the switch S3 is closed to provide a circuit through the wire 3i) and solenoid 2i) when the starting or cut switch S5 is closed. Such closing causes the valve V to shift to its left-hand position, in which liquid is delivered to the upper end of the cylinder I2 and a down working stroke is initated.

At the start of the stroke, all of the tumblers 42 and 5I are in their initial or normal position, as shown in Figs. 9 and l0 and at the top in Fig. l, and the switches SI to S5 are also positioned as shown.

The switch S4 is closed by the dog D4 (Fig. 2) during the down stroke, and at the end of the down stroke the switch S3 is opened by the dog D3, thus breaking the circuit through the wire 3B. The valve V then returns to mid position and the cutting stroke is stopped at mid length. At the same time, the circuit through the holding coil CI is broken, thus allowing the switch S5 to return to normal open position, all as shown in Fig. 2.

Manual depression of the cross bar in the switch S' will then close a circuit through the wire 3|, switches S9 and S4 and the solenoid 2|. The parts then assume the position shown in Fig. 3, in which the valve V is shifted to the right to reverse the hydraulic connections to the cylinder I2 and to cause the piston II, together with the broach holder I0 and the roughing breaches, to return to initial or raised position.

At the end of the up stroke, the dog D4 opens the switch S4, thus breaking the circuit through the wire 3| and solenoid 2| and allowing the valve V to return to its mid or neutral position. This stops further upward movement.

The piston and broach holder I0 are then in their original or extreme raised positions. The work can now be changed and another short or rough cut can be initiated.

If, however, it is desired to follow the roughing cut immediately with a nishing cut in an adjacent broaching range, the rough switches S1 and S9 are opened and the finish switches S8 and SIU are closed by moving all of these switches simultaneously downward manually by means of the knob 35. The parts are then in the position shown in Fig. 4. A second closing of the out switch S5 will then complete a circuit through the switches S3 and SI and the solenoid 20 to shift the valve V again to the left and to thus cause the piston II and broach helder I0 to continue their downward er cutting stroke for a finishing operation.

At the end of this nish stroke, the dog Di opens the switch SI, thus breaking the circuit through the wire 30 and releasing the switch S5, which thereafter maintains the cutting circuit open. During the finish stroke, the switch S2 has been closed by the dog D2, so that the return circuit can be completed by closing the switch S6, the position of the parts at the end of the nish stroke being as shown in Fig. 5.

If a single full stroke is desired, instead of separate short roughingr or finishing strokes, the switches SII and SI 2 are shifted manually by the knob 35 to the full-stroke position shown in Fig'. 6, and the switches S1, S8, S9 and SIU are placed manually in their downward or finish position.

The starting switch S5 may then be depressed to close a circuit through the switches S8 and SI and te cause the solenoid 20 to shift the valve V to the left for a down stroke, during which the switch S4 is closed by a dog D4 as indicated in Fig. 4. A dog DI then opens the switch SI at the extreme lower limit of travel f the breaches, thus ending the full-stroke with the parts in the position shown in Fig. 7.

Closing of the return switch S6 then completes a circuit through the switches SII, S4 and the solenoid 2 I, thus shifting the valve V to the right, with the hydraulic connections as shown in Fig. 3. At the end of the return stroke, the dog D4 will open the switch Sli to break the return circuit and this breaking of the circuit will release the switch S6.

It will be noted that for all ranges a cut stroke is initiated by manually closing the switch S5 and that a "return stroke is initiated by manually closing the switch S6. It will also be noted that every cut stroke is terminated by automatic opening of one of the switches SI or S5 by a dog DI or D3, and that every return stroke is terminated by automatic opening of one of the switches S2 or S4 by a dog D2 or D4. The adjustment of these dogs on the breach holder I0 determines the stopping point for each cut or return stroke.

Furthermore, the machine can be selectively controlled as to range and extent of travel by manual shifting of the knobs 35 and 36.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. In a breaching machine, a broach holder having a full-stroke range and having a shortstroke roughing range and a short-stroke finishing range, said roughing and finishing ranges being successively disposed and longitudinally aligned in the direction of travel, and said fullstroke range combining said two short-stroke ranges, hydraulic power means effective to reciprocate said broach holder in a straight path in said short-stroke roughing range, said shortstroke finishing range or said full-stroke range, valve mechanism and ceacting manually-adjustable dogs therefor effective to determine the range and stroke in which said breach holder is te be reciprocated, valve mechanism and manually-operable control devices therefor effective te start the cut and return strokes of said broach holder in the selected range, and additional and automatically-operated mechanism effective to stop said breach holder at predetermined points at both ends of any selected range.

2. A breaching machine as set forth in claim 1, in which additional manual means is effective to define full-stroke or short-stroke reciprocation of said broach holder.

3. A breaching machine as set forth in claim 1, in which a dog adjustably mounted on said broach holder determines the end of the selected broaching stroke.

4. A breaching machine as set forth in claim 1, in which dogs adjustably mounted on the broach holder separately determine both ends of short short-length and full-length breaching strokes.

5. A breaching machine as set forth in claim 1, in which dogs adjustably mounted on the broach holder separately determine both ends of short roughing strokes, short finishing strokes, and full-length strokes.

6. A breaching machine as set forth in claim 1, in which simultaneously-movable, manually-operated switches are effective to define full-stroke or short-stroke reciprocation of said broach holder.

7. A breaching machine as set forth in claim 1, in which simultaneously-movable, manually-operated switches are effective to determine reciprocation of said breach holder in its roughing range or in its finishing range,

MYER FOX.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 22,099 Harrington et al. May 19, 1942 1,684,139 Oakley Sept. 11, 1928 1,684,140 Perkins Sept. 1l, 1928 2,209,608 Nye et al. July 30, 1940 2,302,791 Monroe Nov. 24, 1942 2,459,697 Halborg Jan. 18, 1949 

